[1] Univ Utah, Dept Radiol & Imaging Sci, Salt Lake City, UT USA
[2] Univ Utah, Dept Neurosurg, Salt Lake City, UT USA
[3] Univ Utah, Dept Pharmaceut & Pharmaceut Chem, Salt Lake City, UT 84112 USA
[4] Univ Calif San Francisco, Dept Radiol & Biomed Imaging, San Francisco, CA 94143 USA